Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 91, NWS Green Bay, WI

September 7, 2021Brown County, Outagamie County, Wisconsin

NWS Green Bay, WI issued this severe thunderstorm warning at Sep 7, 2021, 8:42 AM CDT for Brown County, Outagamie County, Wisconsin. It was in force for 48 min. 23 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 7, 2021, 8:42 AM CDT (13:42 UTC)
Expired
Sep 7, 2021, 9:30 AM CDT
In force
48 min
Issued by
NWS Green Bay, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Brown County, WI, Outagamie County, WI

The radar

The Green Bay radar (KGRB), 12 km from the middle of the area, began a volume at 13:41 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Sep 7, 8:45 AM CDTHAIL 1.75Mackville, WI
Sep 7, 8:45 AM CDTHAIL 2.56 N Appleton, WITENNIS BALL SIZED HAIL OF 2.4 TO 2.5 INCHES. SIX MILES NORTH OF THE APPLETON AIRPORT. HAIL HITTING THE GROUND AND BREAKING.
Sep 7, 8:45 AM CDTHAIL 44 W Mackville, WICORRECTS LOCATION AND SIZE OF TENNIS BALL SIZED HAIL FROM PREVIOUS REPORT. HAIL OF 4.1 INCHES WAS MEASURED. SIX MILES NORTH OF THE APPLETON AIRPORT. HAIL HITTING THE GROUND AND BREAKING.
Sep 7, 8:46 AM CDTHAIL 34 N Appleton, WIREPORT FROM FOX VALLEY LUTHERAN HIGH SCHOOL. TIME ESTIMATED BY RADAR.
Sep 7, 8:47 AM CDTHAIL 34 Nne Appleton, WINORTH OF APPLETON ON THE INTERSECTION OF JJ AND E.
Sep 7, 8:47 AM CDTHAIL 3.752 Nnw Kaukauna, WI
Sep 7, 8:47 AM CDTHAIL 4.255 Nne Appleton, WI4.5 INCH HAIL MEASURED. REPORT VIA SOCIAL MEDIA. TIME ESTIMATED BY RADAR.
Sep 7, 8:47 AM CDTHAIL 4.55 Nne Appleton, WICORRECTS SIZE OF THE PREVIOUS HAIL REPORT FROM 5 NNE APPLETON. 4.5 INCH HAIL MEASURED. REPORT VIA SOCIAL MEDIA. TIME ESTIMATED BY RADAR.
Sep 7, 8:48 AM CDTHAIL 2.752 Ene Mackville, WIBROKE HOME WINDOW.
Sep 7, 8:50 AM CDTHAIL 15 Sse Black Creek, WIONE INCH OR GREATER HAIL NEAR HIGHWAY S AND 47.
Sep 7, 8:50 AM CDTHAIL 2.52 S Mackville, WINORTH SIDE OF APPLETON.
Sep 7, 8:55 AM CDTHAIL 2.75Freedom, WI
Sep 7, 8:57 AM CDTHAIL 2Wrightstown, WI
Sep 7, 8:59 AM CDTHAIL 2.5Wrightstown, WI
Sep 7, 9:02 AM CDTHAIL 1.51 Se Little Rapids, WI
Sep 7, 9:04 AM CDTHAIL 1.51 N Greenleaf, WI
Sep 7, 9:06 AM CDTHAIL 12 N Appleton, WILOCATED APPROXIMATELY 1 MILE EAST OF MEADE STREET AND NORTHLAND AVENUE. TIME OF REPORT ESTIMATED.
Sep 7, 9:10 AM CDTHAIL 15 Nne Appleton, WINORTHEAST SIDE OF APPLETON AT JJ AND FRENCH ROAD.
Sep 7, 9:10 AM CDTHAIL 22 N Appleton, WIOCCURRED AT NORTHLAND AVENUE AND MEADE STREET.
Sep 7, 9:12 AM CDTHAIL 1.52 N Appleton, WI
Sep 7, 9:13 AM CDTHAIL 43 Nne Kimberly, WICORRECTS THE TIME OF THE PREVIOUS HAIL REPORT FROM 3 NNE KIMBERLY.
Sep 7, 9:20 AM CDTHAIL 0.75Wrightstown, WI
Sep 7, 9:27 AM CDTHAIL 43 Nne Kimberly, WI

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 1.7 hours before the alert went out and 11 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Green Bay/Straub, WI at 12:00Z on 2021-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 14 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Green Bay/Straub, WI at 12:00Z on 2021-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -120 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
14 J/kg
Mixed-layer CIN
-216 J/kg
Mixed-layer LCL
1012 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-120 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

907 
WUUS53 KGRB 071342
SVRGRB
WIC009-087-071430-
/O.NEW.KGRB.SV.W.0091.210907T1342Z-210907T1430Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Green Bay WI
842 AM CDT Tue Sep 7 2021

The National Weather Service in Green Bay has issued a

* Severe Thunderstorm Warning for...
  Brown County in northeastern Wisconsin...
  Central Outagamie County in northeastern Wisconsin...

* Until 930 AM CDT.

* At 841 AM CDT, a severe thunderstorm was located 7 miles south of
  Black Creek, or 8 miles northwest of Appleton, moving east at 55
  mph. One inch hail was observed near New London around 825 am.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Appleton around 845 AM CDT.
  Kaukauna, Little Chute and Kimberly around 850 AM CDT.

Other locations in the path of this severe thunderstorm include
Bellevue Town and Denmark.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4447 8863 4462 8782 4433 8777 4433 8789
      4431 8789 4426 8858
TIME...MOT...LOC 1341Z 259DEG 50KT 4437 8849 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Cooley
3 follow-up statements
271 
WWUS53 KGRB 071347
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
847 AM CDT Tue Sep 7 2021

WIC009-087-071430-
/O.CON.KGRB.SV.W.0091.000000T0000Z-210907T1430Z/
Brown WI-Outagamie WI-
847 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 AM CDT
FOR BROWN AND CENTRAL OUTAGAMIE COUNTIES...

At 846 AM CDT, a severe thunderstorm was located near Black Creek, 
or 7 miles north of Appleton, moving east at 60 mph. Tennis ball 
size hail was reported 6 miles north of the Appleton Airport.

HAZARD...Two inch hail and 60 mph wind gusts.

SOURCE...Spotter reported.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

This severe storm will be near...
  Kaukauna around 850 AM CDT.

Other locations in the path of this severe thunderstorm include
Bellevue Town and Denmark.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4447 8863 4462 8782 4433 8777 4433 8789
      4431 8789 4426 8858
TIME...MOT...LOC 1346Z 259DEG 50KT 4438 8839 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...2.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Cooley
027 
WWUS53 KGRB 071405
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
905 AM CDT Tue Sep 7 2021

WIC009-087-071430-
/O.CON.KGRB.SV.W.0091.000000T0000Z-210907T1430Z/
Brown WI-Outagamie WI-
905 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 AM CDT
FOR CENTRAL BROWN AND CENTRAL OUTAGAMIE COUNTIES...

At 904 AM CDT, a severe thunderstorm was located 8 miles southwest 
of Bellevue Town, or 11 miles south of Green Bay, moving east at 55 
mph. At 859 am tennis ball size hail was reported near Wrightstown.

HAZARD...Tennis ball size hail and 60 mph wind gusts.

SOURCE...Trained weather spotters.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
  Denmark.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

This is a dangerous storm. Prepare immediately for large destructive
hail capable of producing significant damage. People outside should
move to a shelter, inside a strong building and away from windows.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4445 8863 4447 8862 4456 8781 4433 8777
      4433 8789 4431 8789 4431 8792 4426 8858
TIME...MOT...LOC 1404Z 266DEG 47KT 4436 8807 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...2.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Cooley
728 
WWUS53 KGRB 071418
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
918 AM CDT Tue Sep 7 2021

WIC009-087-071430-
/O.CON.KGRB.SV.W.0091.000000T0000Z-210907T1430Z/
Brown WI-Outagamie WI-
918 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 AM CDT
FOR CENTRAL BROWN AND SOUTHEASTERN OUTAGAMIE COUNTIES...

At 918 AM CDT, a severe thunderstorm was located near Kaukauna, or 12
miles east of Appleton, moving east at 60 mph.

HAZARD...Tennis ball size hail and 60 mph wind gusts.

SOURCE...Trained weather spotters.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Green Bay, Appleton, Kaukauna, Little Chute, Kimberly, Denmark,
Bellevue Town, Oneida, De Pere and Ashwaubenon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

This is a dangerous storm. Prepare immediately for large destructive
hail capable of producing significant damage. People outside should
move to a shelter, inside a strong building and away from windows.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4431 8860 4449 8841 4456 8781 4433 8777
      4433 8789 4431 8789 4426 8858
TIME...MOT...LOC 1418Z 262DEG 57KT 4432 8815 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...2.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KLJ

The office that day

Everything else NWS Green Bay, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 7, 2:16 AM CDTSpecial Weather StatementGRBVilas89 min
Sep 7, 3:08 AM CDTSpecial Weather StatementGRBVilas97 min
Sep 7, 3:38 AM CDTSpecial Weather StatementGRBOneida, Vilas67 min
Sep 7, 4:22 AM CDTSpecial Weather StatementGRBFlorence, Forest, Langlade, Lincoln38 min
Sep 7, 5:23 AM CDTSpecial Weather StatementGRBMarinette, Menominee, Oconto52 min
Sep 7, 6:09 AM CDTSpecial Weather StatementGRBDoor, Oconto51 min
Sep 7, 6:17 AM CDTSpecial Marine WarningGRB88 min
Sep 7, 8:04 AM CDTSpecial Weather StatementGRBOutagamie, Waupaca41 min
Sep 7, 8:11 AM CDTSevere Thunderstorm WarningGRBOutagamie, Waupaca49 min
Sep 7, 8:16 AM CDTSpecial Marine WarningGRB59 min
Sep 7, 8:28 AM CDTSpecial Weather StatementGRBKewaunee62 min
Sep 7, 8:42 AM CDTSpecial Marine WarningGRB63 min
Sep 7, 9:02 AM CDTSevere Thunderstorm WarningGRBWaushara, Winnebago43 min
Sep 7, 9:09 AM CDTSevere Thunderstorm WarningGRBBrown, Kewaunee, Manitowoc36 min
Sep 7, 9:16 AM CDTSevere Thunderstorm WarningGRBBrown, Calumet, Manitowoc, Outagamie, Winnebago44 min
Sep 7, 9:19 AM CDTSpecial Marine WarningGRB86 min
Sep 7, 9:30 AM CDTSevere Thunderstorm WarningGRBCalumet, Manitowoc, Winnebago60 min
Sep 7, 9:48 AM CDTSpecial Weather StatementGRBKewaunee27 min
Sep 7, 10:18 AM CDTSevere Thunderstorm WarningGRBCalumet, Manitowoc42 min
Sep 7, 10:23 AM CDTSpecial Marine WarningGRB52 min
Sep 7, 11:14 AM CDTSpecial Marine WarningGRB26 min
Sep 7, 6:05 PM CDTSpecial Weather StatementGRBOneida, Vilas40 min
Sep 7, 6:44 PM CDTSpecial Weather StatementGRBForest, Oneida46 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.